yea, I think most college classes are sort of teach yourself. We may have a semblance of a lecture, but they cover an immense amount of material in a small amount of time and only cover the concepts. The homework requires a mastery of the concepts. Suffice to say, it takes many many hours of self-teaching and many sessions in my professor's office every week to survive class. I'm not dumb. I get A's. It's just really really hard sometimes, and we need to learn to cope with the environment. Don't give up is my only advice. I spend over 30 hours a week studying for my multivariable class a week. The teacher is just really difficulty, but I get by.
I would also highly recommend reading and studying the material that will be covered in the next class before you arrive. This way you will have had time to implicitly digest the material, making the second attempt at learning the material much easier.